TM 5-3805-260-242. Make an adjustment to the load valve to get 100 psipressure.3. Write down the oil temperature and the flow rate(gpm).Test 25: Pump Flow at High Pressure (1/2 Test rpm)1. Run the engine at ½ Test rpm.2. Slowly close load valve to get 1000 psi pressure.3. Write down the oil temperature and flow rate (gpm).Make a comparison of the test data with the dataon Charts C1, C2, C3 for specific pump under test. Theinformation on Charts Cl, C2, C3 is for best pumpperformance.TroubleshootingPROBLEM: Percent of flow loss for Test 23 is 10% ormore; for Test 4 through 7 it is morethan the percent shown in Chart A.PROBABLE REASON:Pump has a problem and leakage is in thecontrol valve, valve circuits and/or cylinders.RECOMMENDATION FOR ACTION:Find pump problem. Install a new or rebuiltpump, if necessary. Do the Blocked Circuit Tests to findleakage rate in the control valve, valve circuits and/orcylinders.PROBLEM:Percent of flow loss for Test 23 is 0 to10%; for Tests 4 through 7 it is more thanthe percent shown in Chart A.PROBABLE REASON:Pump is in good condition, but there is leakagein control valve, valve circuits and/or cylinders.RECOMMENDATION FOR ACTION:Do the Blocked Circuit Tests to find leakage ratein control valve, valve circuits and/or cylinders.PROBLEM: Percent of flow loss for Test 23, Chart C2 is15% or MORE; for Test 23, Chart C3, flow loss is 10% orless.PROBABLE REASON:A large amount of elevator speed control valveleakage.RECOMMENDATION FOR ACTION:Remove the speed control valve. Disassemblethe control valve and inspect the parts. Repair or replaceparts as necessary.PROBLEM: Percent of flow loss for Test 23 is 10% orMORE. Flow differential for Test 23 ishigher than the flow differential for Test25 by 0 to 2 gpm.PROBABLE REASON:Pump is worn.RECOMMENDATION FOR ACTION:If flow loss is found to be too high for themachine application, install a new or rebuilt pump.PROBLEM: Percent of flow loss for Test 23 is 10%oor MORE. Flow differential for Test 23 ishigher than flow differential for Test 25by 2 gpm or MORE.PROBABLE REASON:A. Oil aeration (low oil level, hydraulic oil that isnot the correct type, air leak in the suctionline for the pump, oil leaks in the tank suchas failure of seals or loose connections).B. Pump cavitation (restriction in the suction linefor the pump, oil viscosity that is notcorrect).RECOMMENDATION FOR ACTION:Do Tests 26 through 30 to find if the reason isaeration or cavitation.Pump Test for Aeration and CavitationTests 26 through 30: Aeration and Cavitation TestsThese seven tests are similar. Do the tests asfollows:1. Open the manual load valve fully, then start the dieselengine.2. Run the engine at the test rpm for Test 26.3. Slowly close the manual load valve to get 1000 psipressure.4. Write down the flow rate (gpm) and the oiltemperature.5. Then run the engine at test rpm (for Tests 27, 28, 29and 30).6. Write down the flow rate (gpm) and oil temperaturefor each test.4-46